A few years ago I attempted to export all my rides from Garmin Connect in .gpx or .tcx format, so I could import into Strava. It worked for most of my rides, but plenty, especially some long rides, were only exported as 2kb files, with the whole ride missing, the files looking like this 244km ride which I was unable to import into Strava:
>
<?xml version="1.0" encoding="UTF-8"?>
<TrainingCenterDatabase
xsi:schemaLocation="www.garmin.com/.../v2 ">www.garmin.com/.../TrainingCenterDatabasev2.xsd"
xmlns:ns5="">www.garmin.com/.../v1"
xmlns:ns3="">www.garmin.com/.../v2"
xmlns:ns2="">www.garmin.com/.../v2"
xmlns="">www.garmin.com/.../v2"
xmlns:xsi="">www.w3.org/.../XMLSchema-instance" xmlns:ns4="">www.garmin.com/.../v1">
<Activities>
<Activity Sport="Biking">
<Id>2007-12-28T17:44:35.000Z</Id>
<Lap StartTime="2007-12-28T17:44:35.000Z">
<TotalTimeSeconds>37281.7</TotalTimeSeconds>
<DistanceMeters>244443.7</DistanceMeters>
<MaximumSpeed>21.9</MaximumSpeed>
<Calories>34945</Calories>
<AverageHeartRateBpm>
<Value>141</Value>
</AverageHeartRateBpm>
<MaximumHeartRateBpm>
<Value>169</Value>
</MaximumHeartRateBpm>
<Intensity>Active</Intensity>
<TriggerMethod>Manual</TriggerMethod>
<Extensions>
<ns3:LX>
<ns3:AvgSpeed>6.556667212063828</ns3:AvgSpeed>
</ns3:LX>
</Extensions>
</Lap>
</Activity>
</Activities>
<Author xsi:type="Application_t">
<Name>Connect Api</Name>
<Build>
<Version>
<VersionMajor>0</VersionMajor>
<VersionMinor>0</VersionMinor>
<BuildMajor>0</BuildMajor>
<BuildMinor>0</BuildMinor>
</Version>
</Build>
<LangID>en</LangID>
<PartNumber>006-D2449-00</PartNumber>
</Author>
</TrainingCenterDatabase>
----------------
I've tried a number of times since, but always with the same result.
Why does this happen, and can it be fixed?